1. Field of the Invention
This invention relates to a method, a device and a computer program for designing a circuit having both electronic circuits connected by electric wires and optical circuits using optical connections as integral components thereof (to be also referred to as optoelectronic circuit).
2. Related Background Art
Recently, information processing devices including personal computers, mobile phones and personal digital assistants (PDAs) have been required to operate at high processing speed in addition to be compact and lightweight. However, as the processing speed rises, problems arise to the circuits thereof, including wiring delays, EMI (electromagnetic interference) noises and so on. Techniques have been proposed to utilize optical circuits using optical connections in order to avoid wiring delays, EMI noises and other problems (see, inter alia, Japanese Patent Application Laid-Open No. H6-308519).
Meanwhile, information processing devices and robot controllers are required to be capable of switching a plurality of control algorithms on a real time basis for the control operation. From this point of view, there is a demand for reconfigurable circuits that can operate at high speed and switch configuration on a real time basis. Examples of reconfigurable circuits include FPGAs (field programmable gate arrays) and CPLDs (complex programmable logic devices) (see, inter alia, Patent Application Laid-Open Publication No. 2000-311156). However, such circuits need further improvements in terms of high speed operation and circuit size.
FIG. 20 of the accompanying drawings is a flow chart that can generally be employed when designing an information processing device (semiconductor system) of the type under consideration. Generally, a system design is carried out according to a requirement specification and subsequently a circuit connection list (net list) is generated by way of a logical design. Then, the layout (place and route design) of the system is designed and verified. A design method using such a technique for a system having two chips is known (Japanese Patent Application Laid-Open No. 2001-298086). According to the design method, when one or more than one problems are detected as a result of verification, the redesign process goes back to the place and route design or to the system design.
Thus, to realize a sophisticated information processing device or a controller, circuits are required to be of a large scale, operable at high speed and flexible (reconfigurable). The use of a circuit having both electronic circuits connected by electric wires and optical circuits using optical connections as integral components thereof, or an optoelectronic circuit, can meet such requirements.
When designing a system having both optical circuits using optical fibers and optical waveguides and electronic circuits coexist as integral parts thereof, the optical circuits and the electronic circuits are clearly separated from each other and designed independently as shown in FIG. 21 in the initial stages of the system design shown in FIG. 20. However, with such a design technique of designing optical circuits and electronic circuits separately, it is difficult to fully exploit the potentials of the circuits (hardware) of the two categories. To be more accurately, while optical circuits and electronic circuits may be designed optimally, the design of the optoelectronic circuit for integrally combining them is not optimal. Additionally, designing an optoelectronic circuit requires advanced professional knowledge of circuits of the two categories, a vast amount of time and huge cost.